Generally, in a semiconductor device, a well junction may be formed by performing an ion implantation process in order to control the threshold voltage of a transistor. In recent years, as devices are highly integrated, the well junction may be formed by implanting an impurity of a high concentration so as to secure the characteristics of the transistor when the ion implantation process is performed. Further, in forming a Shallow Trench Isolation (STI) layer a STI structure in which trenches may be formed in a semiconductor substrate and then gap filled with an insulating material may be used rather than an existing LOCal Oxidation of Silicon (LOCOS) structure. Thus, etch damage to sidewall of a silicon (Si) substrate due to excessive Si etch is inevitable.
Stress within a channel junction may be increased by implant damage. The increased stress grows into defects due to a subsequent annealing process, thus generating disturbances caused by Transit Enhanced Diffusion (TED). In the case of a flash memory device on which program and erase may be performed using channel boosting, Number Of Program (NOP) fail occurs due to the existence of disturbances within the channel junction. This becomes more severe at certain portions, which becomes a cause of remaining stress within an active region.
Further, a method of gap filling trenches using a Spin on Dielectric (SOD) material as a trench gap-fill material has recently been introduced because of the trench gap-fill limits of a High Density Plasma (HDP) oxide film. In particular, there is a method of fully gap filling trenches using polysilazane (PSZ) that has a low viscosity and a flowing property like water. However, if the trenches are gap filled with the SOD material, dopant segregation may be increased due to the stress of the material and a subsequent annealing process. Accordingly, the leakage current may be increased due to the occurrence of hump. Furthermore, compensation for the lost dopant through additional ion implantation may cause cell disturbances to further increase.